The Disruptive Behavior Disorders (DBD's) and Substance Use Disorders (SUD's) diagnose common serious adolescent problems confronting principles., juvenile court judges and pediatricians. Pilot work suggests there may be a subgroup of DRD adolescents who are (a) recognizable (b) treatable and (c) self medicating with a "gateway drug," marijuana. If replicated, these preliminary findings could have policy implications for substance abuse treatment, special education certification and family court sentencing. Screening criteria identify DBD adolescents with temper outbursts and mood swing who improved in pilot studies on divalproex sodium (Depakote), a mood stabilizer and anticonvulsant. Those who used substances preferred marijuana, saying it helped them calm down. This relief from irritability may make marijuana a gateway to career addiction for this particular type of DBD teenager. In pilot studies, a steep drop in self-report marijuana use followed divalproex treatment in these adolescents. Since some components of marijuana have anticonvulsant properties and some anticonvulsants are mood stabilizers, divalproex may work by being a better mood stabilizer than marijuana. The aim is to randomize 120 DBD adolescents (age 12-20) to a six week double blind, placebo parallel groups study to test two hypotheses: (1) DBD Adolescents meeting specified screening criteria for temper outbursts and mood swings greater reduction in these symptoms on divalproex sodium (Depakote) than on pill placebo. (2) Marijuana use in these adolescents will significantly decline after treatment with Depakote. Seventy subjects will abuse marijuana at baseline. A community-based referral network was built during the pilot phase. It consists of guidance counselors and special education administrators from the school system, plus nurses, social workers, and pediatricians from adolescent medicine. If this study's results are as predicted, they may help build algorithms on diagnosis, treatment and referral of the DBD's and SUD's.